Magnetic liquid display panel

ABSTRACT

A magnetic display panel is provided, including strips of first electrodes arranged in the first direction on the inner surface of a rear plate. Strips of second electrodes are arranged in the second direction perpendicular to the first electrodes while being insulated from the first electrodes. Pixel electrodes are each installed on the intersection of a first electrode and a second electrode, and each has a spiraled magnetic field producing unit electrically connected to the first and second electrodes. A magnetic film is formed on the pixel electrodes, and has a magnetic gap through which a magnetic field produced by the pixel electrodes leaks. Magnetic fluid is formed to a predetermined thickness on the inner surface of the rear plate. Such a display panel can provide moving pictures because of its improved responsivity, and, particularly, is easily fabricated at a low cost in large quantities because of its simple structure. Furthermore, the display panel is advantageous in constituting super-large display devices based on multiple integration.

TECHNICAL FIELD

[0001] The present invention relates to the field of magnetic liquiddisplay panels, and more particularly, to a magnetic liquid displaypanel that has a high responsivity and is easily manufactured.

BACKGROUND ART

[0002] Display devices have been developed from cathode ray tubes (CRTs)using an accelerated electronic beam to plasma display panels (PDPs)based on plasma discharge, and liquid crystal displays (LCDs) usingliquid crystal having an electro-optical effect. Besides, there arevacuum fluorescent displays (VFDs) using an electronic beam acceleratedat a low speed, electro luminescent displays (ELDs), and magnetic liquiddisplay panels. These display devices are classified into an activedisplay device, which radiates light by itself, and an inactiveluminescent display device, which requires a light source because thedisplay device cannot emit light by itself.

[0003] LCDs, which are recently used for laptop computers, arerepresentative of inactive luminescent display devices, and compact andlight and consume a small amount of power. Accordingly, LCDs are widelyused in compact electronic products as well as lap-top computers. SuchLCDs have the above-mentioned merits, but also have the demerit that itsmanufacturing process is complicated due to the use of liquid crystal.In particular, in order that air bubbles do not remain on a liquidcrystal layer existing between a front plate and a rear plate, which area predetermined distance apart from each other, liquid crystal injectionis performed by a complicate vacuum injection method using adifferential vacuum pressure. The cavities of unit LCDs must be isolatedfrom one another by partitions with certain widths in order to receiveliquid crystal injected in a vacuum environment by the above-mentionedvacuum injection. Accordingly, when a large-screen display device ismanufactured with several unit LCDs, the junction portion betweenadjacent unit LCDs occupies a significantly large effective area becauseof the partitions with certain widths. This degrades the continuity ofan image on the unit LCDs. Also, LCDs must be formed of a materialendurable against high heat since they undergo a high-temperatureprocess. In addition, a complicate manufacturing process makes itdifficult to produce large LCDs.

[0004] Like LCDs, magnetic liquid display panels are also classifiedinto a non-emissive display device. As well known, magnetic fluid(ferromagnetic fluid) is suspension in which superfine ferromagneticparticles are stably dispersed within a liquid. The ferromagneticparticles are not separated from the liquid under a general centrifugalforce or a general magnetic field. Magnetic fluid is magnetic colloid,which operates like having a magnetism within a magnetic field. The typeof Magnetic fluids includes oxide magnetic fluid and metallic magneticfluid. An example to which such magnetic fluid is applied is disclosedin European Patent No. 0633488 A1, in which a display panel adopts aprinciple similar to that of existing LCDs.

[0005] To be more specific, as shown in FIG. 1, magnetic fluid 4 isinterposed between a front plate 1 and a rear plate 2. a plurality ofmagnetic field coils 3 for applying a magnetic field to the magneticfluid 4, in which geometrically anisotropic magnetic particles aredispersed, are installed behind the rear plate 2. the magnetic fieldcoils 3 are coupled to a display controller 5 for driving the magneticfield coils. The magnetic field coils 3 are also provided in a structurewhere loop-shaped patterns stacked on a multi-layered substrate areconnected to one another by through holes. In such a display panel, asshown in FIG. 2, the magnetic particles at portions ON, which aresupposed to transmit light 6, are aligned by the application of amagnetic field to the portions ON, thus transmitting light. Meanwhile,portions OFF, in which magnetic particles are naturally scattered, aresupposed to absorb or block light.

[0006] However, it is extremely difficult that the magnetic particles inthe magnetic fluid used in such a conventional display panel havegeometric anisotropy under a superfine state. also, light control basedon the alignment or non-alignment of magnetic particles is not smooth.In addition, the magnetic field coils 3 for applying a magnetic field tomagnetic fluid must be formed in a multi-layered structure, thusrequiring a very complicate manufacturing process.

[0007] In a magnetic fluid display panel disclosed in U.S. Pat. No.3,863,249, instead of using the alignment or nonalignment of magneticfluid, light transmission is blocked or allowed depending on thepresence or absence of magnetic fluid within a light transmission areadue to the movement of magnetic fluid by a magnetic force. However, thismagnetic fluid display panel requires a strong magnetic field to movemagnetic fluid, and accordingly requires high energy power. Also, themagnetic fluid display panel is very inferior in terms of pixelswitching responsivity by magnetic fluid, hence it is not suitable toform moving pictures. In addition, since the magnetic fluid displaypanel adopts magnetic coils as a magnetic field forming unit, theminiaturization of cells, and mass-production are difficult, and themanufacturing costs are high.

[0008] The inventor of the present invention has proposed a new magneticfluid display panel through U.S. Pat. No. 5,912,652, in order toovercome the defects of such conventional magnetic display panels.

[0009] The aforementioned magnetic display panel can provide movingpictures with a fast responsivity, and also can be easily manufacturedat a low cost in large quantities because of its simple structure.Furthermore, this magnetic display panel is significantly advantageousin the construction of super-large display devices by multipleintegration. The present invention provides a magnetic display panelimproved in performance based on such a magnetic display panel describedabove.

DISCLOSURE OF THE INVENTION

[0010] A first object of the present invention is to provide a displaypanel capable of providing moving pictures with an increasedresponsivity.

[0011] A second object of the present invention is to provide a magneticdisplay panel that can be easily manufactured at a low cost in largequantities because of the simplicity of its structure.

[0012] A third object of the present invention is to provide a magneticdisplay panel that is advantageous in constituting a super-large displaydevice based on multiple integrations.

[0013] In order to achieve the above objects of the present invention,there is provided a magnetic display panel according to an aspect of thepresent invention. In this magnetic display panel, front and rear plateskeep a predetermined distance from each other. Strips of firstelectrodes are arranged in the first direction on the inner surface ofthe rear plate. Strips of second electrodes are arranged in thedirection perpendicular to the first electrodes while being insulatedfrom the first electrodes. Pixel electrodes are each installed on theintersection of a first electrode and a second electrode, and each has aspiraled magnetic field producing unit electrically connected to thefirst and second electrodes. An upper magnetic film is formed on thepixel electrodes, and has a magnetic gap through which a magnetic fieldproduced by the pixel electrodes leaks. Magnetic fluid is formed to apredetermined thickness on the inner surface of the rear plate.

[0014] Preferably, the upper magnetic film is formed of a soft magneticmaterial. It is also preferable that each of the pixel electrodes has aplurality of magnetic field producing units electrically connected toone another.

[0015] Preferably, 2 magnetic gaps for each magnetic field producingunit are formed in the upper magnetic film, and each of the magneticgaps is formed halfway between the center of a magnetic field producingunit and either lateral side of the magnetic field producing unit.

[0016] Also, preferably, a magnetic shield layer, which corresponds to alower magnetic film, is formed of one of a soft magnetic material and aferromagnetic material under the pixel electrodes. Furthermore, it ispreferable that the magnetic shield layer and the upper magnetic filmform a closed-loop-shaped magnetic circuit.

[0017] In order to achieve the above objects of the present invention,there is provided a magnetic display panel according to another aspectof the present invention. In this magnetic display panel, front and rearplates keep a predetermined distance from each other. Strips of firstelectrodes are arranged in the first direction on the inner surface ofthe rear plate. Strips of second electrodes are arranged in thedirection perpendicular to the first electrodes while being insulatedfrom the first electrodes. Pixel electrodes are each installed on theintersection of a first electrode and a second electrode, and each has aspiraled magnetic field producing unit electrically connected to thefirst and second electrodes. A lower magnetic film is formed on thepixel electrodes, and has a magnetic gap through which a magnetic fieldproduced by the pixel electrodes leaks. An upper magnetic film is formedof a ferromagnetic material over the lower magnetic film. Magnetic fluidis formed to a predetermined thickness on the inner surface of the rearplate.

[0018] Preferably, the lower magnetic film is formed of a soft magneticmaterial. It is also preferable that each of the pixel electrodes has aplurality of magnetic field producing units electrically connected toone another.

[0019] Preferably, 2 magnetic gaps for each magnetic field producingunit are formed in the upper magnetic film, and each of the magneticgaps is formed halfway between the center of a magnetic field producingunit and either lateral side of the magnetic field producing unit.

[0020] Preferably, a magnetic shield layer is formed under the pixelelectrodes. Furthermore, it is preferable that the magnetic shield layerand the upper magnetic film form a closed-loop-shaped magnetic circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIGS. 1 and 2 are schematic block diagrams of a conventionaldisplay panel using magnetic fluid;

[0022]FIG. 3 is a schematic plan view of the configuration of first andsecond electrodes formed on a rear plate in a magnetic display panelaccording to the present invention;

[0023]FIG. 4 is a schematic enlarged plan view of pixel electrodesinstalled on a pixel area on which first and second electrodes intersectat right angles, in the magnetic display panel of FIG. 3;

[0024]FIG. 5 is a schematic enlarged plan view of a pixel electrode inthe magnetic display panel of FIG. 4;

[0025]FIG. 6 is a partial cross-section of a magnetic display panelaccording to a first embodiment of the present invention, taken alongline A-A′ of FIG. 5;

[0026]FIG. 7 is a plan view of a magnetic gap formed on an uppermagnetic film in the magnetic display panel according to the firstembodiment of the present invention;

[0027]FIG. 8 is a schematic cross-section of the magnetic display panelaccording to the first embodiment of the present invention;

[0028]FIGS. 9A and 9B are cross-sectional views for explaining the ONand OFF states of pixels in the magnetic display panel according to thefirst embodiment of the present invention;

[0029]FIG. 10 is a schematic cross-section of a multi-layered structureformed on a rear plate in a magnetic display panel according to a secondembodiment of the present invention;

[0030]FIG. 11 shows a computer simulation showing a magnetic fielddistributed in a magnetic field production unit in the magnetic displaypanel of FIG. 10; and

[0031]FIGS. 12A through 12K are cross-sectional views for illustrating arear plate formation process in the manufacture of a magnetic displaypanel according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0032] In FIG. 3, first electrodes X₁ through X_(n) (hereinafter,referred to as X) and second electrodes Y₁ through Y_(n) (hereinafter,referred to as Y) are arranged on a rear plate 10 in a magnetic displaypanel according to the present invention. FIG. 4 enlarges and showspixel electrodes 30 formed on pixel areas on which the first and secondelectrodes X and Y intersect at right angles are shown. FIG. 5 enlargesand shows a pixel electrode 30.

[0033] As shown in FIGS. 3 and 4, the first electrodes X are arranged ina row on the rear plate 10 at a predetermined interval, while the secondelectrodes Y lie at right angles to the first electrodes X. Accordingly,the first and second electrodes X and Y establish an X-Y matrixstructure as that used in general flat display devices.

[0034] The first and second electrodes X and Y are electricallyinsulated from one another, and the pixel electrodes 30, which are thefeature of the present invention, are formed on the pixel areas wherethe first and second electrodes X and Y intersect. In FIGS. 4 and 5, apixel electrode 30 has four magnetic field producing units 31 a and 31 bspiraled in a rectangular shape, among which every two magnetic fieldproducing units 31 a and 31 b form a group and are electricallyconnected to each other in series. Here, the magnetic field producingunits 31 a and 31 b are electrically insulated from the first and secondelectrodes X and Y by an unshown insulating layer. However, only theends 32 a and 32 b of the magnetic field producing units 31 and 31 b areelectrically connected to the first and second electrodes X and Ythrough an unshown hole penetrating the insulating layer. Such aconnection structure will be described in detail later.

[0035] The magnetic field producing units 31 a and 31 b in each of thepixel electrodes 30 are connected to the first and second electrodes Xand Y to produce a magnetic field using an operation voltage receivedthrough the first and second electrodes X and Y.

[0036] As described above, each of the pixel electrodes 30 may have aplurality of magnetic field producing units, for example, four magneticfield producing units 31 a, 31 b, 31 a and 31 b shown in FIGS. 4 and 5,but it may have a single magnetic field producing unit in some cases.According to the present invention, the number of magnetic fieldproducing units for each pixel electrode 30 is not limited and can varyaccording to design conditions. Also, when a plurality of magnetic fieldproducing units are provided for each of the pixel electrodes 30, theycan be individually connected to the first and second electrodes X andY. Alternatively, as described above, two adjacent magnetic fieldproducing units 31 a and 31 b for one group are electrically connectedto each other, and each group with both ends 32 a and 32 b can beconnected to the first and second electrodes X and Y. A magnetic displaypanel according to a first embodiment of the present invention will nowbe described, based on the structure in which two magnetic fieldproducing units 31 a and 31 b for each group are electrically connectedto each other.

[0037]FIG. 6 is a cross-section of part of a magnetic display panelaccording to a first embodiment of the present invention, taken alongline A-A′ of FIG. 5. In FIG. 6, a magnetic field producing unit havinglayers deposited one on another at its upper and lower sides is shown.

[0038] Referring to FIG. 6, the first and second electrodes X and Y areformed on the rear plate 10, while a first insulating layer 11 isinterposed between the first and second electrodes X and Y. A secondinsulating layer 12 is formed on the second electrodes Y, and a lowermagnetic film, that is, a magnetic shield layer 13, is formed of a softmagnetic material on the second insulating layer 12. The magnetic shieldlayer 13 and an upper magnetic film 16 can be formed of a hard magneticmaterial. However, preferably, they are formed of a soft magneticmaterial.

[0039] A third insulating layer 14 is formed on the magnetic shieldlayer 13, and magnetic field producing units 31 a and 31 b, which form apixel electrode 30, are formed on the third insulating layer 14. Afourth insulating layer 15 is formed on a magnetic field producing unit31 a/31 b. The upper magnetic film 16 is formed of a hard magneticmaterial, or, preferably, a soft magnetic material, on the top of theresulting layered structure. The upper magnetic film 16 contacts themagnetic shield layer 13 at the portions unoccupied by the magneticfield producing unit 31 a/31 b, thus constituting a magnetic circuitshaped of a closed loop. A magnetic gap 16 a having no upper magneticfilm 16 is formed in the middle of the center C of the magnetic fieldproducing unit 31 a and either of its periphery. In other words, themagnetic gap 16 a is formed at the portion providing the strongestmagnetic field, out of the entire portion of the magnetic fieldproducing unit 31 a/31 b spiraled in a rectangular shape. The uppermagnetic film 16 directly contacts magnetic fluid. Although theconnection mechanism for connecting the magnetic field producing unit 31a/31 b to the first and second electrodes X and Y is not shown in FIG.6, a through hole is formed on the lower part of the magnetic fieldproducing unit 31 a/31 b, through which the magnetic field producingunit 31 a/31 b is electrically connected to the first and secondelectrodes X and Y. This connection mechanism can be easily formed by ageneral technique, hence it does not limit the scope of the presentinvention.

[0040]FIG. 7 is a plan view of the upper magnetic film 16 of FIG. 6. Asshown in FIG. 7, the magnetic gap 16 a, which is in a rectangular shapecorresponding to the shape of the magnetic field producing unit 31 a, isformed on the upper magnetic film 16.

[0041]FIG. 8 is a schematic cross-section of the magnetic display panelof FIG. 6, in which a front plate has been combined with the rear plate10. A spacer 40 stands on the rear plate 10 to support the front plate20 while interposing between adjacent pixel electrodes 30, such that aspace for receiving magnetic fluid 50 is provided between the front andrear plates 20 and 10. The magnetic fluid 50 is located on the innersurface of the rear plate 10, to be more specific, on the upper magneticfilm 16. Meanwhile, color filters 21 r, 21 g and 21 b for realizingcolor pictures are formed on the inner surface of the front plate 20.

[0042] In such a structure of a magnetic display panel according to thepresent invention, when a strong magnetic field is produced on amagnetic gap by magnetic field producing units, most incident light isreflected by the magnetic field, or when there is no magnetic field,most incident light is absorbed by magnetic fluid. In this way, imagesare displayed.

[0043]FIG. 9A shows the state of the magnetic display panel of FIG. 8when no magnetic field is produced by magnetic field producing units.FIG. 9B exaggeratedly shows the state of the magnetic display panel ofFIG. 8 when a magnetic field is produced by magnetic field producingunits.

[0044] As shown in FIG. 9A, when there is no magnetic field produced bymagnetic field producing units, the magnetic fluid 50 is formed to auniform thickness over the entire surface of the upper magnetic film 16by surface tension. Accordingly, only some of incident light isreflected, whereas the rest is absorbed by the magnetic fluid 50. Thiscases denotes that pixels are in an OFF state, that is, are in a darkstate.

[0045] As shown in FIG. 9B, while magnetic fields are produced bymagnetic field producing units, strong magnetic fields are collected atthe magnetic gap 16 a, and accordingly the magnetic fluid 50 iscollected at the magnetic gap 16 a while it exists very thinly on thearea other than the magnetic gap 16 a. Hence, most incident light isreflected by the upper magnetic film 16, while only some incident lightis absorbed by the magnetic fluid 50. Thus, this case represents thatpixels are in an ON state, that is, are in a bright state. The ON stateof pixels is maintained only while current is being applied to themagnetic field producing units. However, when the supply of current tothe magnetic field producing units is stopped, the magnetic fluidimmediately spreads to the entire surface of an upper magnetic film by asurface tension.

[0046] Such an ON-OFF mechanism of pixels is similar to the ON-OFFmechanism of general liquid crystal displays. The ON-OFF mechanism ofpixels controls the amount of reflection of incident light, and,accordingly, color picture display can be achieved by light beams withwavelengths selected by color filters installed in front of a frontplate.

[0047] The amount of movement of magnetic fluid depends on the amount ofcurrent supplied to the pixel electrodes. This enables controlling ofthe reflective rate of incident light, so that the gray scale can beexpressed.

[0048]FIG. 10 is a partial cross-section of a stacked structure formedon a rear plate 10 in a magnetic display panel according to the secondembodiment of the present invention, in which a ferromagnetic film 18for self memory is formed over the upper magnetic film 16. Referring toFIG. 10, first and second electrodes X and Y are formed on the rearplate 10, while a first insulating layer 11 sandwiches between the firstand second electrodes X and Y. A second insulating layer is formed onthe second electrode Y, and a lower magnetic film, that is, a magneticshield layer 13, is formed of a soft or hard magnetic material on asecond insulating layer 12.

[0049] A third insulating layer 14 is formed on the magnetic shieldlayer 13, and the magnetic field producing units 31 a and 31 b, whichform a pixel electrode 30, are formed on the third insulating layer 14.A fourth insulating layer 15 is formed on a magnetic field producingunit 31 a/31 b. An upper magnetic film 16 is formed of a hard or softmagnetic material on the top of the resulting stacked structure. Theupper magnetic film 16 contacts the magnetic shield layer 13 at theportions unoccupied by the magnetic field producing unit 31 a/31 b, thusconstituting a magnetic circuit shaped of a closed loop. A magnetic gap16 a having no upper magnetic film 16 is formed in the middle of thecenter C of the magnetic field producing unit 31 a/31 b and either ofits periphery. In other words, the magnetic gap 16 a is formed at theportion providing the strongest magnetic field, out of the entireportion of the magnetic field producing unit 31 a/31 b spiraled in arectangular shape.

[0050] A fifth insulating layer 17 is formed on the upper magnetic film16, and a ferromagnetic film 18, which is the feature of the presentinvention, is formed on the fifth insulating layer 17. The ferromagneticfilm 18, which contacts magnetic fluid, is magnetized together with themagnetic fluid when magnetic fields are produced by the magnetic fieldproducing units 31 a and 31 b. The ferromagnetic film 18 also provides aso-called memory function of pixels by maintaining a magnetic force fora certain period of time by virtue of its ferromagnetism regardless ofwhether magnetic fields are produced by the magnetic field producingunits 31 a and 31 b. Hence, without need for continuous application ofcurrent to the magnetic field producing units 31 a and 31 b forachieving the ON/OFF of pixels, current can be applied only for theduration required to magnetize the ferromagnetic film to a requiredintensity.

[0051] In order to erase the information memorized by the ferromagneticfilm 18 from a pixel, that is, to refresh the pixel, the erasingmagnetic field with respect to the ferromagnetic film 18 must beproduced by the magnetic field producing units 31 a and 31 b. Thepolarity of the erasing magnetic field for the ferromagnetic film isinverted as in a general degaussing process, and sinusoidal reducingcurrent, whose intensity decreases, is applied to the magnetic fieldproducing units 31 a and 31 b.

[0052] In FIG. 10, although the connection mechanism for connecting themagnetic field producing unit 31 a/31 b to the first and secondelectrodes X and Y is not shown, a through hole is formed on the lowerpart of the magnetic field producing unit 31 a/31 b, through which themagnetic field producing unit 31 a/31 b is electrically connected to thefirst and second electrodes X and Y. Such a connection mechanism can beeasily formed by a general technique, as mentioned above in thedescription of the first embodiment. Hence, it does not limit the scopeof the present invention.

[0053]FIG. 11 shows the distribution of a magnetic field in a magneticfield production unit through a computer simulation performed on themagnetic display panel of FIG. 10. Referring to FIG. 11, it can be seenthat a magnetic field is produced around a magnetic field producing unitby the application of current to the magnetic field producing unit,while a very strong magnetic field is concentrated on the magnetic gapof an upper magnetic film, through which magnetism leaks. It can also beseen that a lower magnetic film, that is, a magnetic shield layer,shields the magnetic field below the magnetic gap from spreading towarda substrate. The magnetic shield layer is provided to prevent themagnetic field in a pixel electrode from disturbing by an externalmagnetic field. As a result, magnetic fluid is gathered around themagnetic gap where a magnetic field is gathered, resulting in a shape asshown in FIG. 9B. Thus, most incident light beams are reflected.

[0054] Such a magnetic display panel according to the present inventioncan be fabricated by a well-known photolithographic technique.

[0055] A process for fabricating a magnetic display panel according tothe present invention will now be described with reference to FIGS. 12Athrough 12K schematically showing only a magnetic field producing unitfor convenience of explanation.

[0056] As shown in FIG. 12A, a plurality of first electrodes X arearranged side by side in the first direction on a rear plate 10. Next, afirst insulating layer 11 is formed to a predetermined thickness on thefirst electrodes X.

[0057] As shown in FIG. 12B, a plurality of second electrodes Y arearranged side by side in the second direction perpendicular to the firstdirection, on the first insulating layer 11. At this time, a throughhole Y1 for allowing a magnetic field producing unit to contact a firstelectrode X and preventing short-circuit is formed in a second electrodeY.

[0058] As shown in FIG. 12C, a second insulating layer 12 is formed on asecond electrode Y. Next, a lower magnetic film, that is, a magneticshield layer 13, is formed on the second insulating layer 12. At thistime, through holes 131 and 132 for allowing the magnetic producing unitto contact the first and second electrode X and Y and preventing shortcircuit is formed in the magnetic shield layer 13. If the magneticshield layer 13 is formed of an electrical insulating material, thethrough holes 131 and 132 are not needed.

[0059] As shown in FIG. 12D, a third insulating film 14 is formed on themagnetic shield layer 13.

[0060] As shown in FIG. 12E, through holes 501 and 502 are verticallyformed from the third insulating film 14. The through hole 501 isconnected to the through hole 131 of the magnetic shield layer 13, andthe through hole Y1, such that the surface of the first electrode X isexposed. At this time, the magnetic shield layer 31 and the secondelectrode Y must not be exposed through the inner walls of the throughhole 501. Meanwhile, the through hole 502 is formed upon the uppersurface of the second electrode Y through the central area of thethrough hole 132 in the magnetic shield layer 13.

[0061] As shown in FIG. 12F, a metal layer 30 for pixel electrodes isformed on the third insulating layer 14, and it contacts the first andsecond electrodes X and Y through the through holes 501 and 502.

[0062] As shown in FIG. 12G, the metal layer 30 is patterned to obtainthe aforementioned magnetic field producing units 31 a and 31 b byphotolithography and etching.

[0063] As shown in FIG. 12H, a fourth insulating layer 15 is formed onthe third insulating layer 14 and the magnetic field producing units 31a and 31 b. Thereafter, the surface of the fourth insulating layer 15 isplanarized by chemical mechanical polishing.

[0064] As shown in FIG. 121, a predetermined portion of the fourthinsulating layer 15 is removed so that an upper magnetic film 16 to beformed later contacts the magnetic shield layer 13.

[0065] As shown in FIG. 12J, the upper magnetic film 16 is deposited onthe fourth insulating layer 15.

[0066] As shown in FIG. 12K, the aforementioned magnetic gaps 16 a areformed on predetermined areas on the upper surface of the upper magneticfilm 16.

[0067] Through such a process, the stacked structure on the rear plate10 according to the first embodiment of the present invention is formed.

[0068] The stacked structure on the rear plate 10 according to thesecond embodiment can be obtained by an additional process. Such rearplates having stacked structures are each combined with a pre-fabricatedfront plate 20 at a predetermined distance, thereby obtaining a magneticdisplay panel according to the present invention.

INDUSTRIAL APPLICABILITY

[0069] The above-described display panel according to the presentinvention can provide moving pictures because of its responsivity betterthan that of a reflective display panel, and, particularly, is easilyfabricated at a low cost in large quantities because of its simplestructure. Furthermore, such a display panel is advantageous inconstituting super-large display devices based on multiple integration.

[0070] While this invention has been particularly shown and describedwith reference to preferred embodiments thereof, it will be understoodby those skilled in the art that various changes in form and details maybe made therein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A magnetic display panel comprising: front andrear plates keeping a predetermined distance from each other; strips offirst electrodes arranged in the first direction on the inner surface ofthe rear plate; strips of second electrodes arranged in the directionperpendicular to the first electrodes while being insulated from thefirst electrodes; pixel electrodes each installed on the intersection ofa first electrode and a second electrode, the pixel electrodes eachhaving a spiraled magnetic field producing unit electrically connectedto the first and second electrodes; an upper magnetic film formed on thepixel electrodes, the upper magnetic film having a magnetic gap throughwhich a magnetic field produced by the pixel electrodes leaks; andmagnetic fluid formed to a predetermined thickness on the inner surfaceof the rear plate.
 2. The magnetic display panel of claim 1, wherein theupper magnetic film is formed of a soft magnetic material.
 3. Themagnetic display panel of claim 1, wherein each of the pixel electrodeshas a plurality of magnetic field producing units electrically connectedto one another.
 4. The magnetic display panel of any of claims 1 through3, wherein 2 magnetic gaps for each magnetic field producing unit areformed in the upper magnetic film, and each of the magnetic gaps isformed halfway between the center of a magnetic field producing unit andeither lateral side of the magnetic field producing unit.
 5. Themagnetic display panel of any of claims 1 through 3, wherein a magneticshield layer, which corresponds to a lower magnetic film, is formed of amagnetic material under the pixel electrodes.
 6. The magnetic displaypanel of claim 4, wherein a magnetic shield layer, which corresponds toa lower magnetic film, is formed of a magnetic material under the pixelelectrodes.
 7. The magnetic display panel of claim 5, wherein themagnetic shield layer and the upper magnetic film form aclosed-loop-shaped magnetic circuit.
 8. The magnetic display panel ofclaim 6, wherein the magnetic shield layer and the upper magnetic filmform a closed-loop-shaped magnetic circuit.
 9. A magnetic display panelcomprising: front and rear plates keeping a predetermined distance fromeach other; strips of first electrodes arranged in the first directionon the inner surface of the rear plate; strips of second electrodesarranged in the direction perpendicular to the first electrodes whilebeing insulated from the first electrodes; pixel electrodes eachinstalled on the intersection of a first electrode and a secondelectrode, the pixel electrodes each having a spiraled magnetic fieldproducing unit electrically connected to the first and secondelectrodes; a lower magnetic film formed on the pixel electrodes, thelower magnetic film having a magnetic gap through which a magnetic fieldproduced by the pixel electrodes leaks; an upper magnetic film formedover the lower magnetic film; and magnetic fluid formed to apredetermined thickness on the inner surface of the rear plate.
 10. Themagnetic display panel of claim 9, wherein the upper and lower magneticfilms are formed of a soft magnetic material.
 11. The magnetic displaypanel of claim 9, wherein each of the pixel electrodes has a pluralityof magnetic field producing units electrically connected to one another.12. The magnetic display panel of any of claims 9 through 11, wherein 2magnetic gaps for each magnetic field producing unit are formed in theupper magnetic film, and each of the magnetic gaps is formed halfwaybetween the center of a magnetic field producing unit and either lateralside of the magnetic field producing unit.
 13. The magnetic displaypanel of any of claims 9 through 11, wherein a magnetic shield layer isformed of a ferromagnetic material under the pixel electrodes.
 14. Themagnetic display panel of claim 12, wherein a magnetic shield layer isformed of a ferromagnetic material under the pixel electrodes.
 15. Themagnetic display panel of claim 13, wherein the magnetic shield layerand the upper magnetic film form a closed-loop-shaped magnetic circuit.16. The magnetic display panel of claim 14, wherein the magnetic shieldlayer and the upper magnetic film form a closed-loop-shaped magneticcircuit.